Question

solution	[NH4+], M	NH3], M	ΔpH on adding H+	pH on adding H+	Initial pH	pH on adding OH	ΔpH on adding OH-
a	0.10	0	2.43	2.13	4.56	9.07	4.51
b	1.0	0	2.12	2.09	4.21	8.37	4.16
c	0.050	0.050	1.14	8.38	9.52	10.06	0.54
d	0.50	0.50	0.17	9.52	9.69	9.73	0.04
e	0	0.10	0.78	9.62	10.4	11.39	0.99
pure water			2.39	2.26	4.65	12.06	7.41

Sorry I know that this is a lot but having trouble with this part. I know my ph for water is off. Is there a way to correct this for estimated values?

If the solution is diluted more than 10-fold, which solution — 1.0 M NH4Cl (solution B) or 0.50 M NH4Cl + 0.50 M NH3 (solution D) — does the pH change more?

Explain, on the basis of the Ka expression, why dilution has less effect on the pH of a buffer solution than on the pH of a solution containing only the acid as a solute (here NH4+).

Effect of Added H3O+ and OH- on a Buffer Compare the values of ΔpH for solutions C and D with the values of ΔpH for A,B and E.

Which solutions show a buffering action? How can you tell? What a balanced chemical equation for each reaction that prevents a large change in pH (buffers).

Answer 1